By Euan McKirdy, CNN

(CNN) -- Zimbabwe's 93-year-old leader, his 52-year-old wife and his veteran VP -- who was cast aside after years of loyal service -- are some of the key figures in an unfolding political crisis gripping what used to be one of Africa's richest countries.

The sudden appearance of the military on the streets of Zimbabwe's capital on Tuesday night in an apparent coup comes a week after Robert Mugabe fired his powerful right-hand man Emmerson Mnangagwa.

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While the world's oldest president has maintained an iron grip on the country since he led it to independence in 1980, many Zimbabwe watchers see Mugabe at perhaps his most vulnerable in decades.

Here's a look at the key players:

President Robert Mugabe

Mugabe has been in control of the country for almost four decades -- first as Prime Minister and then as President.

For the 1980s and part of the 1990s he was feted at home and abroad, but gradually became more authoritarian and by 1993 had instituted the Land Acquisition Act permitting the government to force white farmers to give up their land for redistribution to black Zimbabweans.

Since then he has presided over mass inflation and food shortages brought about by his disastrous land reallocation programs.

As conditions in Zimbabwe worsened and accusations of human rights abuses escalated, institutions around the world, including the British Crown, stripped him of honors previously bestowed on him.

In July of this year Mugabe urged his ruling ZANU-PF party to ensure that his legacy remains "long after" he is "gone."

Emmerson Mnangagwa

Mnangagwa, known has "Ngwenya" or the "Crocodile" to many because of his well-honed survival instincts, was with Mugabe from the start. He's been Mugabe's right-hand man for nearly four decades, first as his assistant during the liberation struggle, later as his intelligence chief, then cabinet minister and all-round enforcer.

Mnangagwa had previously been considered most likely to succeed Mugabe if the president stepped down or died while in office.

Mnangagwa has a strong following in Zimbabwe's powerful military and amongst war veterans who fought in the liberation struggle, and has been a key strategist for Mugabe in past elections, says David Coltart, a former cabinet minister and opposition leader.

But earlier this month Mugabe accused Mnangagwa of "disloyalty, disrespect, deceitfulness and unreliability," in a move to pave the way for his wife, Grace, to succeed him.

First Lady Grace Mugabe

Born in South Africa, Mugabe's second wife has developed a reputation as a shrewd, if sometimes extravagant, politician in her own right.

Given the moniker "Gucci Grace" by Zimbabweans for her exorbitant shopping trips, she has been a polarizing figure in a country wracked with poverty. Despite this, she has long had the support of younger politicians in the country's political hierarchy.

Mnangagwa's sudden dismissal was seen by many as a way for the President to appoint his wife, Grace, to the position, prompting widespread discontent among formerly loyalist supporters.

"Grace Mugabe without Robert Mugabe will not survive a single day politically. But as long as Mugabe is there, she will do what she wishes," says Alex T. Magaisa, a lecturer at Kent University and former aide to ex-Prime Minister Morgan Tsvangirai.

Her youngest sons are regulars in the high-flying party scene in South Africa's economic capital, frequently making gossip headlines for their antics on social media.

And the prospect of a being led by the current first lady is an anathema to many in Zimbabwe's old guard, who tie links to the armed struggle with political credibility.

Minister for Defense Sydney Sekeramayi

Minister for Defense Sydney Sekeramayi is "believed to be a contender for the vice presidency and is considered a dark horse in the succession drama," Tinashe Jakwa, a Southern Africa analyst at the African Studies Association of Australasia and the Pacific (AFSAAP) said.

"His elevation to the VP post would be a strategic move to curb perceptions of a Mugabe dynasty."

Gen. Constantino Chiwenga

The nation's army commander, Chiwenga denounced the firing of the vice president and other "members associated with our liberation history."

On Tuesday he held a press conference in which he threatened to intervene should his political allies continue to be sidelined, warning that if the purge of senior ZANU-PF officials did not stop, "the military will not hesitate to step in."

In response to the conference, ZANU-PF, accused Chiwenga of "treasonable conduct."

Maj. Gen. S.B. Moyo

The Army Chief of Staff became the face of the political turmoil late Tuesday when he appeared on Zimbabwean state TV to assure citizens that their country was not in the throes of a coup.

"To both our people and the world beyond our borders, we wish to make it abundantly clear that this is not a military takeover of government," he said.

"What the Zimbabwe Defense Forces is doing is to pacify a degenerating political, social and economic situation in our country, which if not addressed may result in a violent conflict."

In the broadcast, Moyo spoke of targeting "criminals" around the President.

Morgan Tsvangirai

Former Prime Minister and trade unionist Morgan Tsvangirai entered government as part of a power-sharing agreement from 2009-2013, where he served as chairman of the council of ministers and deputy chairman of the cabinet as well as prime minister.

In the late 1990s, however, he was a trenchant opponent of Mugabe and his ZANU-PF party and organized general strikes in protest at the government's management of the country.

His Movement for Democratic Change (MDC) party was launched two years later. He campaigned under difficult, often violent circumstances, was jailed for treason several times and severely beaten by Mugabe supporters on a number of occasions. He claimed victory in a 2008 election but pulled out, claiming it had "been marred by the widespread intimidation, torture, mutilation and murder of his supporters."

However, after successful negotiations, Mugabe and Tsvangirai signed the Global Political Agreement, which stated Tsvangirai will become prime minister and Mugabe will remain president, commander-in-chief and chairman of the cabinet. He left the power-sharing agreement in 2013, again claiming widespread fraud in that year's election.